Experimental Diels–Alder Reactivities of Cycloalkenones and Cyclic Dienes Explained through Transition‐State Distortion Energies

Quantum chemical calculations are used to investigate the experimentally measured reactivities of cyclic dienes and cycloalkenones in the Diels–Alder reaction. The interaction energies (red) are nearly constant; differences arise in changes in distortion energies of both dienophile (blue) and diene (green; see picture, Ea=activation energy; values in kcal mol−1).